border-collapse

Resumo

The border-collapse property is used to make the border collapse. This has a big influence on the look and style of the table cells.
The rendering of table borders is divided into two categories in CSS2 - "collapsed" and "separated". This property specifies which border rendering mode to use. In the collapsed border model, adjacent table cells share borders.
In the separated model, adjacent cells each have their own distinct borders (the distance between them given by the 'border-spacing' property.)

Exemplos

Notas

In the "collapsed border" rendering model, the 'border-style' value of "inset" behaves like "groove", and "outset" behaves like "ridge." CSS2 specifies that the initial value for this property is "collapse", but CSS2.1 and Mozilla/Opera all state or behave such that the initial value is "separate."